Drawing sheet glass



Jan. 1, 19 29.

C. P. BYRNES DRAWING SHEET GLASS Original Filed June, 8. 1921 2 Sheets-Sheet cwm Jan. 1, 1929.

C. P. BYRNES DRAWING SHEET GLASS Original Filed June 8. 1921 2 Sheets-Sheet 2 Patented Jan. 1, 1929.

UNITED STATES 1,697,194 PATENT OFFICE.

CLARENC E'P. B YRNES, OF SEWIGKLEY, BENNSYLVANIA.

DRAWING SHEET GLASS.

Application filed June 8, 1921 Serial No. 476,053. Renewed January 15, 1926.

Figure 1 is a diagrammatic longitudinal section showing a portion of the apparatus arranged for carrying out my invention;

Figure 2 is an elevation showing one form of the bending rolls and drag rolls; and

Figures 3, 4 and 5 are top plan views showing modified forms.

My invention relates to the drawing of sheet glass over a bending roller. by which it is bent from a generally vertical direction to a generally horizontal direction and to that type of such drawing wherein the bending roll is either cut away at its central portion so as not to contact with the sheet glass, or is formed of separate stub rollers.

In such a system the sheet glass tends to sag at its intermediate portion between the stub rolls or over the cut away portion of a single bending roll. My invention is designed to overcome this and to impart a side tension or pulling to the sheet glass in this general portion so as to prevent or remove any sagging of the glass and keep it flatter.

In the drawing, referring to the form 0 Figures 1 and 2, 2 represents the end portion of a tank furnace which extends to the rightof the figure. 3, 3 are water coolers to cool and set the rising sheet. The sheet is preferably drawn with thickened edge portions which are preferably en aged just above the meniscus by friction rake devices, shown as pairs of rolls' 4, 4, projecting inwardly from the sides and engaging these thickened edge portions. These stub rollers may be provided with an suitable amountof friction or drag by bra e devices applied to their portions exterior to the drawing chamber. They thus impart any desired amount of dra or tension to the sheet as it rises. In this form the bendingroll is cut away at an intermediate portion 5,

leaving larger end portions 6 with which the thickened edge portions of the sheet contact. After passing over the bending roll system the sheet is drawn horizontally, preferably through a flattening chamber and then through an annealing chamber by any desirable means.

In this first form I show skewed tension rollers 7, 7, the shafts of which extend through the walls of the chamber and may be driven in any suitable manner. The axes of these stub rollers are inclinedto the axes of the bending roller so that as they rotate they put a slde tension in opposite directions on the sheet passing over the bending roller, thus tending to remove sag and also to possibly thinthe sheet somewhat.

In Figure 3 the bending roller is shown as consisting of two stub rollers 6, the parts otherwise being the same as in Figures 1 and 2.

In the form of Fignre 4, both the bending roll s 6 and the stretching rollers 7", with their axes substantially parallel, incline to the direction of travel.

In the form of Fi e 5 I show a bending roller of the type of igures 1 and 2 and employ skewed rollers 7 in pairs with their axes parallel immediately in the rear of the bending rolls.

In all these cases the object is the same, namely, to impart a side strain or stretching action to the sheet in opposite directions in the region of the bending roller.

' Suitable heating burners may be employed wherever desire either in the drawing chamberor otherwise, to assist in reheating the glass sheet.

1 The advantages of my invention result :trom the use of means for stretching the glass as it passes over a bending roll system and particularly in connection witha bending roll system which avoids contact with the intermediate portion of the sheet and allows for sagging thereof.

The bending roll system may be driven or not as desired; the drag rolls may be driven or not as desired, but the stretching rolls are preferably positively driven.

Other means may be used for imparting a stretching or side pulling tendency to the sheet in the region 0 the bending roll without departing from my invention.

I claim:

1. An apparatus for drawing sheet glass means for drawin the sheet glass in a generally vertical ire'ction and then in a generally horizontal direction over a bending roll system, the bending roll system allowing sag of the intermediate portion of the sheet, and means 'for imparting side strains to the sheet in the region of the bending roll system, substantially as dea-vrioec.

2. An apparatus for drawing sheet glass, means for drawing the sheet glass in a generally vertical direction and then in a generally horizontal direction over a bending roll system, the bending roll system allowing sag of the intermediate portion of the sheet, and skewed rollers arranged to impart continuous side strains to the sheet in the region of the bending roll system, substantially as described.

3. An apparatus for the continuous drawing of sheet glass over a bending roll, a bending roll system arranged to contact with the thickened edge portion only of the sheet, and skewed rollers adjacent the bending roll system the skewed and tension rolls being arranged to impart side strains to the sheet in the region of the bending roll system, substantially as described.

4. In the method of drawing sheet glass, the steps consisting. in bending the sheet from one plane to another while unsupported except at its edges by gripping the edge portions of the sheet between members which engage the sheet throughout the bending operation, and applying lateral tension to the glass sheet, substantially as described.

'5. In the method of drawing sheet glass, the steps consisting in first drawing the sheet upwardly and then bending the sheet into a substantially horizontal plane while uh supported except adjacent its edges, and applying lateral tension to theeglass sheet during the drawing thereof, substantially as described.

6. That improvement in the art of. drawing sheet glass, which consists in bending the sheet from one. plane to another ;while unsupported ekcept at its edges, by applying lateral tension to the sheet during the bend ing operation.

7 That improvement in the art of drawing sheet glass, which consists in bending the sheet from one plane to another while unsupported except at its edges, by engaging the sheet edges and drawing the same forwardly and outwardly during the bending operation.

8. That'improvement in the art of drawing a continuous sheet of glass from a molten source, consisting in first drawin the sheet upwardly and then bending thesiheet into a substantially horizontal plane, the main central portion of the sheet being unsupsite edge portions of the sheet being drawn forwardly with the sheet and also outwardly, away from the center line of the sheet during the bending operation.

10. In a sheet glass drawing apparatus, means for bending the sheet from one plane to another, comprising means for engaging the sheet edges and drawing them forwardly and outwardly during the bending operation.

In testimony whereof, I have hereunto set my hand.

C. P. BYRNES. 

